Corps cares for critters

Amber Tilton
Park Ranger, The Dalles Lock and Dam

The American Kestrel, native to Oregon, is a secondary-cavity-nesting bird, which Portland District has protected from becoming trapped in our vault toilet ventilation pipes by installing vent screens. (Photo by Kathy Snodgrass)

Every year, thousands of cavity-nesting birds become trapped in vertical ventilation pipes, chimneys and other dark, narrow spaces. Cavity-nesting bird species, which include woodpeckers, chickadees, owls, ducks and falcons typically make their homes in dead or rotting tree wood.

A recently dead tree will first be used as home to woodpeckers, known as primary excavators. Woodpeckers chip away at the tree to create a cavity as part of their annual courtship and nesting behavior. As the wood softens and decays, secondary cavity nesters, birds that cannot make their own cavities, move in. The American kestrel, and some species of ducks and owls, are examples of birds that rely on these existing cavities for their nesting and reproductive cycle.

Vault toilets, found on public lands including many Corps recreation locations, have vertical ventilation pipes that mimic the natural cavities preferred by some birds. Unfortunately, these man-made cavities often entrap birds looking for a nesting site.

In 2009, an employee of the Audubon Kern River Preserve in California reported finding a fallen irrigation standpipe, 6 inches in diameter and 10 feet long that contained the remains of over 200 dead birds. The ventilation pipes on vault toilets are 12 inches in diameter.

Portland District has installed ventilation screens or caps on our vault toilets to protect the 27 species of cavity-nesting birds that are native to our region. The ventilation screens were purchased from the Teton Raptor Center, located in Jackson Hole, Wyo. The TRC is a nonprofit organization that raised nationwide awareness of this cavity-nesting bird issue with the launch of their Poo-Poo Project. The Corps cares for all of our visitors, including those that have wings and talons.

A screen covers the ventilation pipe of a vault toilet. The screens are designed to stand off of the pipe to allow venting around the side in the event the top of the screen becomes obstructed with snow or debris. (Photo courtesy of the Teton Raptor Center)